This invention relates generally to the field of flow control devices, and more particularly to a valve mechanism for a tank, and especially for a multiple tank arrangement having a flow control valve within each tank.
It is known to provide a plurality of fuel tanks on locomotive engines, with a fuel pump drawing fuel from each of the tanks simultaneously. In many applications, there is no flow control device used in the fuel line from the respective fuel tanks. In such an arrangement, when one of the tanks becomes empty, the fuel pump will draw air from that tank in lieu of fuel, thereby starving the engine of its necessary fuel supply. Once one tank becomes empty, cavitation in the fuel pump will prevent it from drawing the remaining fuel from the tanks that are not yet empty.
To overcome this problem, it is known to provide a flow control device such as an electronic solenoid valve within the fuel line from each respective tank. When a tank is nearly empty the respective fuel line solenoid valve may be closed prior to drawing air from that tank. However, such devices are complicated and relatively expensive, and have a probability of failure that is a function of the reliability of the separate fuel level measuring device and the electronic solenoid valve. Thus, there is a particular need for a fluid flow control arrangement for a plurality of fluid storage tanks that will permit a maximum amount of fuel to be drawn from the tanks and that is inexpensive to build and reliable to operate.